- 1 Status on OpenStreetMap
- 2 1987 Channel Tunnel
- 2.1 Route
- 2.1.1 Tunnels
- 2.1.2 Adits
- 2.1.3 Shafts
- 2.1.4 Cross Passages
- 2.1.5 Technical Rooms
- 2.1.6 Piston Relief Ducts
- 2.1.7 Crossovers
- 2.1.8 Pumping stations
- 2.1.9 Notional locations
- 2.2 Mapping
- 2.3 Fires
- 2.1 Route
- 3 References
- The 1880 Channel Tunnel  was an experimental 820-metre narrow-bore tunnel, started from a horizontal adit at Chapel-le-Ferne.
- The 1881 Channel Tunnel was an experimental 1,865-metre narrow-bore tunnel started from a vertical shaft at Shakespeare Cliff heading towards the Dover Harbour walls.
- The 1882 Channel Tunnel was an experimental 1,669-metre narrow-bore tunnel started at Sangatte.
- The 1974 Channel Tunnel was an experimental medium-bore tunnel started from a sloping Adit A1  at Shakespeare Cliff, plus an experimental medium-bore sloping adit started from Sangatte.
- The 1987 Channel Tunnel is the present-day final result and consists of one medium and two large bores.
The 1881, 1974 and 1987 service bores all coincide at an underwater point off Aycliff—here the 1974 bore forms a section of the latter-day 1987 service tunnel and the 1881 tunnel crosses on the same level at an oblique angle.
Status on OpenStreetMap
Whilst a huge amount of academic work was published during the construction phase, putting it in the "public knowledge" domain, there is no dataset under a licence that can be imported directly into OpenStreetMap. GPS does not work in the tunnel. We do however have a large number of numerical facts to work from; this page attempts to compile those. The only organisations with that dataset in electronic form are likely to be Eurotunnel Groupe, SNCF International (Mauzin, IRIS 320 track recording train) or the Inter-Governmental Commission (deposited plans). For data-logging, it would appear that at least  some  journalists  have been allowed to drive electric cars through the service tunnel as a gimmick, and a car with a high-precision inertial measurement unit could source data for the service tunnel. The same could be done with a gyro/IMU on a standard Le Shuttle or Eurostar crossing as other people have suggested for other underground tunnels. LiDAR from one of the open Arbel HGV wagons should work too. The Channel Tunnel is significantly longer than any other tunnels that might have been tried with a IMU though, so the error drift is going to be somewhat larger.
The present status (May 2013) is that the 1987 Channel Tunnel is pretty well mapped from general knowledge, and Eurotunnel's two terminals are accurately mapped from Bing satellite coverage. If the newly-installed GSM/3G network gets picked up for geo-location with modern phone-based satnavs, it should be possible to semi-accurately animate the moving route correctly while the Shuttle is under the sea. The route is tagged with Proposed features/shuttle_train for the Eurotunnel Shuttle ro-ro service and two additional parallel hidden ways for routeing (see OSRM example). Motorbikes/coaches/cars/motorhomes need to use the Tourist shuttles and tourist-entrances, for the moment this is done with
hgv=no. Additional hidden routes exist for bicycles, as these are picked up at an arranged meeting point in a Eurotunnel-branded people-mover+trailer unit (sub-contracted out to M W Cave of Hythe who kindly confirmed the pick-up points and routeing), and driven through inside the Tourist Shuttle. These have separate pick-up points so two more hidden ways exist to enforce cycle routeing; exit bicycle routeing is not done yet as it is unclear what happens for drop-off.
Physically the service tunnel correctly weaves around the two running tunnels at the undersea crossovers and these and the tunnel's intermediate accesses at Shakespeare Cliff and Sangatte are included. The location of the tunnel line itself is probably off by +/-1 kilometre in the mid-sections where it is following the Chalk Marl, as are the wiggles in the French section through the faults. Closer to the coasts it should be more accurate. The Ordnance Survey released Open Street Raster (1:10k) which has an under-land curve of mostly the correct width and an alignment to within ~50 metres of the prior OSM data—although its accuracy is unclear: has incorrect positioning undersea, and it does not include the widened profiles through Castle Hill/Holywell and the Shakespeare Underground Development.
Previous contact with at Eurotunnel's Press Office (by Paul Sladen in March 2012), was roughly that if we could find a dataset (ie, already in the public knowledge) and Eurotunnel still owned the rights (verses TML) Eurotunnel could look into allowing a use for OpenStreetMap. In the mean-time, it's still possible to tweak and improve the mapping, and much like the Tube network, it may well end up being reasonably complete anyway. The questions that were raised by John Keefe at Eurotunnel were:
- That the ET route is not simple (eg. the MST swapping sides)
- That the the data may not readily exist (require sanitising first)
- More information about the rationale/reason/basis (why mapping in detail on OSM)
Eurotunnel previously provided the general arrangement "Reference Alignment Plan BETU 0900" (revised: 3 July 1991) to the Ordnance Survey.
1987 Channel Tunnel
The present-day 1987 Channel Tunnel Fixed Link runs east—west for 50.5 kilometres from Folkestone/Kent in England to Coquelles/Calais in France. It consists of three parallel tunnel bores, Running Tunnel North (RTN), Marine Service Tunnel (MST), Running Tunnel South (RTS) constructed at 15-metre centres. The outer two bores are the railway running tunnels and contain 1,435mm standard gauge track with a design speed-limit of 160 km/h, and overhead 50Hz 25Kv AC electrification, with a loading gauge far in excess of GC and the overhead wire at an above-normal height. The railway tunnels are bi-directional, but normally drive on the left. The centrally placed service tunnel is a two-lane private road for electric vehicles with a speed limit of 50 km/h, where vehicles drive on the left (as in the UK) and an embedded wire system available for steering. Change from left-to-right-hand driving takes place in the French airlock (AL6049).
The outer two bores are linked to the central service tunnel bore via pedestrian Cross Passages (CP), nominally every 375 metres, which have strong locked strong fireproof blast doors (normally closed). The outer two bores are also linked to each other using narrow-diametre Pressure Relief Ducts (PRD) every 250 metres; these follow a vertical arc and pass over the top of the service tunnel without connecting to it and have butterfly isolation doors (normally open). The two running tunnel bores are linked at rail-level are four locations, a facing single crossover under Castle Hill, a trailing single crossover under Holywell Coombe, an undersea scissors crossover at the UK Crossover cavern, and an undersea scissors crossover at the France UK crossover. The undersea crossover caverns are blocked by pairs of very large sliding doors (normally closed), keeping the two tunnels atmospherically separated.
- Castle Hill Portal, within the Eurotunnel Folkestone secure compound (CH 10+025)
- Castle Hill Tunnel, NATM construction, three bores, service tunnel below and to south
- Holywell Tunnel, cut-and-cover construction, three bores, service tunnel crosses under RTS to middle. A20 trunk road over top on viaduct.
- UK-landside tunnels, TBM construction, three bores
- Shakespeare Cliff Shaft, ventilation building (CH 19+257)
- Adit A2 (1987) sloped connection to surface at Samphire Hoe facilities
- Adit A1 (1974) sloped connection to surface at Samphire Hoe facilities
- 1881 tunnel crossing-point, on the level (blocked off)
- UK Crossover Cavern (CH 27+000—CH 27+150)
- Point 'X', construction mid-point (CH 35+300)
- Border CH 37+000.
- International border (RTS: CH37+881, ST: CH37+902, RTN: CH37+916)
- Point 'M', the meeting place and mid-tunnel international border zone area
- French Crossover Cavern
- Sangatte Shaft, ventilation building (CH 57+247)
- French-landside tunnels, TBM construction, three bores, service tunnel crosses over RTN to north side
- Beussingue Portal, nice-looking double-circular portal in the deep Beussingue cutting, within the Eurotunnel Coquelles secure compound. These two portals are the ones used in publicity (CH 60+518, or PK 59+495(?) or CH60+472.)
It is not straight, under land it curves to meet the shafts at Shakespeare Cliff and Sangatte while under water it twists and turns to stay in within the Lower Chalk Marl strata and avoid the Fosse Dangeard, which runs ~500 metres south of the tunnel between chainage 38 and 42 and a subsidiary crosses over the top at chainage 39.
There are three separate tubes: Running Tunnel North, the Service Tunnel and Running Tunnel South. Each tube is the linear combination of multiple tunnel headings. RTN and RTS are nominally identical mirror copies at offsets of +/-15 metres with respect to the service tunnel:
|FR Marine||(0+091—18+860) T1||-15.0||(0+089—15+617) T3||+15.0||(0+091—20+011) T2||TBM|
|FR Land||(‒0+089—3+265) T4||-15.0||(‒0+089—3+251) T5||+15.0||(‒0+091—3+265) T6||TBM|
Distances in (parentheses) are westerly from Sangatte shaft rather than chainage from the east. Construction methods—C&C: Cut and Cover; FF: False Façade; NATM: New Austrian Tunnelling Method; TBM: Tunnel Boring Machine; TD: Top-Down. The service tunnel passes over RTN at (PM -2920) with 3.45 m of separation.
There is a single service tunnel. It has an internal diameter of 4.8 metres (or 4.930 m) and its centreline is 0.9 metres below the centreline of the Running Tunnels, with the floor 0.58 metres above the floor of the Running Tunnels. It is formed from the end-to-end connection of seven individual tunnel headings: Castle Hill Tunnel (from Holywell Combe), Holywell Cut-and-Cover (from open air), Land Servce Tunnel (from Shakespeare Cliff), 1974 Channel Tunnel section, Marine Service Tunnel (from Shakespeare Cliff), Marine Service Tunnel (T1 from Sangatte), Land Service Tunnel (T4 from Sangatte).
At Castle Hill Portal it has an airlock AL1014, with doors MVT1008 and MVT1014. Through Castle Hill it has a centre-line 15 metres south of Running Tunnel South. Through Holywell it crosses under RTS to move to the middle position. At Shakespeare cliff it narrows as it uses the 1974 Channel Tunnel bore. At the two crossover caverns it dips down, and crosses under Running Tunnel North before returning to the middle position in each case. At the mid-point of the UK crossover cavern it is 7.45 metres below the centre-point of the running tunnels, and 40 metres north. Near Beussingue it rises and crosses over Running Tunnel North to a separate airlock numbered AL6043/AL6049, followed by a false portal above and to the north of the running tunnel façades. Each tunnel lining ring is 1.5 metres (or 1.5068 m) in length on the British side, and 1.4 metres (or 1.4012 m) in length on the French side.
The service tunnel has a designed minimum horizontal curve of 1,000 metres; in the bored sections this is limited to a minimum 4,000-metre horizontal radius around the UK crossover, and 2,000-metre radius around the French crossover plus 2,000 metres at the French portal. The gradient of the service tunnel near Castle Hill portal is 3.5% for two lengths for 21 metres and 217 metres. Near the Beussingue portal is 2%. The Service tunnel has vertical radius of 3,000 metres and maximum gradient of -3.496% inside Castle Hill West portal, which switches to -1.071% after a widening for staired cross-passage.
Through the Shakespeare Underground Development area, the service tunnel centreline is 14.9 metres from RTS and 20.1 metres from RTN. The 1975 service tunnel section (250 metres, or 432 metres) has a diameter of 4.5 metres, and the land-side service-tunnel bore has a diameter of 4.9 metres.
In two campaigns during 1989 Deutsche Montan Technologie (DMT) undertook traverse validation surveys of service tunnel drive using gyro-theodolite. The first of these was in March 1989 and used the zig-zag surveying station brackets affixed to the tunnel wall, this survey suffered from optical refraction in the horizontal plane. The second campaign at the end of December 1989 used mid-tunnel positions to avoid refraction. Norbert Korittke of DMT published several academic papers over the variations between the optical reckoning and bearings from the gyro-theodolite. Tables of factual bearing, ring-count and distance for the first 6 kilometres, and 13 kilometres respectively, out-to-sea from the base of Adit A2 are provided. These have a precision of below 1 metre over the traverse and show the zig-zag traverse neatly jumping 2-metres back-and-forth across the later centre-line traverse—the large-radius curve around the UK crossover cavern is also clearly visible. In a second paper on the subject, the gyro and optical bearing columns are reversed without comment—with Korittke having died in 2004 (following a long illness), clarification may not be possible. Norbert Korittke's Doctoral Thesis published in 1997 also includes a paper with bearings for the September 1990 survey covering chainages Ch31–Ch40, which continues on from the second survey. Bearings are in w:Gradians to True North:
- Second-campaign traverse distances differ by 190–191 metres between different copies of the paper for rings 5546–8544. It would appear that traverse distances may not be true traverse distances, but probably derived purely from the tunnel ring number once inside the bored tunnel. If this is the case, a spreadsheet typo may be the cause.
There are two running tunnels. These have an internal diameter of 7.6 metres (or 7.860 m), and are formed from the end-to-end connection of six individual tunnel headings: Castle Hill Tunnel (from Holywell Combe), Holywell Cut-and-Cover (from open air), Land Running Tunnel (from Shakespeare Cliff), Marine Running Tunnel (from Shakespeare Cliff), Marine Running Tunnel (from Sangatte), Land Running Tunnel (from Coquelles). These are positioned with the centre nominally 15 metres from the centre of the service tunnel except at the portals and crossovers. Each tunnel lining ring is 1.5 metres in length on the British side, and 1.6 metres in length on the French side.
Through Castle Hill the Running Tunnels are built on 20.25-metre centres. At the crossover caverns the two Running Tunnels are on 10.5-metre centrelines from each other, with the Marine Service Tunnel to the north. At the pumping stations, the two running Tunnels are on 19.0-metre or 20.0-metre centres (CH25.0) or 21.5-metre (CH34.8) centrelines from the service tunnel. The minimum vertical curve is a 15,000-metre parabola. The minimum horizontal curve is 6,000 metres, and these are joined by clothoid track transition curves. Minimum gradient is 0.18% for drainage purposes.
Running Tunnel Gradient profile, relative to an approximate initial datum of 260 metres (CTD, OD + 60 m) at Castle Hill Portal/approximately 205 metres (CTD, OD - 28 m) at Beussingue portal. The linear chainage compared to a hypothetical flat surface route is on the order of one 1 metre of error which is far less than the present mapping.
|Chainage (km)||Gradient (m/km)||Chainage (km)|
There are two sloping adits connecting to the surface. These run eastwards and slope downwards from the Eurotunnel technical compound at Samphire Hoe (base of Shakespeare Cliff) to the extensive Shakespeare Underground Development (SUD).
Adit A1(1975) is 490 metres long and runs parallel to the Shakespeare Cliff mainline railway tunnels. It descends and passes above Adit A2 at an oblique angle.
Adit A1 carries four chiller loops. The first heads inland in RTS and loops back 827 metres from Castle Hill Portal. The second heads out to sea in RTS to the tunnel mid-point. The third heads inland in RTN and loops back 2500 metres from Castle Hill Portal. The fourth heads out to sea in RTN to the tunnel mid-point.
Adit A2(1988) is 7 metres high and 12.5 metres wide. It has a gentler slope of 15% and runs more north-easterly direction passing over the 1881 Channel Tunnel, then crossing 8 metres below Adit A1, and then also diagonally under the Shakespeare Cliff mainline tunnels. It was built to house five narrow-gauge construction railway tracks side-by-side. It forms part of the Supplementry Ventilation System.
Of the three construction shafts, two remain and now house the normal (NVS) and supplementary ventilation systems (SVS). The SVS locations are given as PK 54.14 and PK 21.82 (although these the chainages look a bit suspect).
Upper Shakespeare Cliff
The remanant Upper Shakespeare Cliff Shaftforms part of the UK component of the Normal Ventilation System. It is 106 metres deep and 10.0 metres diameter. The shaft portal is immediately to the north of the A20 road where descends vertically and is connected to the Service Tunnel. It is at chainage 19+257.
A slightly earlier second shaft 110 metres deep and 9.25 metres internal diameter existed for personnel access, leading down to the bottom of Adit A2. This was capped off after construction.
Sangatte Shaft  The running and service tunnels are 45 metres below ground level at this point. It is at Chainage 57+247. The normal ventilation system ducting (NVS, Système de ventilation normal) is smaller and on the south side. The supplementary ventilation system ducting (SVS, Système de ventilation supplémentaire) is larger and on the north side.is 65 metres deep, and 55 metres in diameter.
The Sangatte Shaft SVS zone covers PK 5705‒5744. The shaft carries, NVS, SVS and three chiller loops (circuits de refrigeration with cold water (d'eau glacée). The first heads out to sea in RTN to the tunnel mid-point and loops back. The second heads out to sea in RTS to the tunnel mid-point and loops back. The third heads inland in RTN and loops back 827 metres from Beussingue Portal to Sangatte shaft, then heads inland to in RTS and loops back 2500 metres before Beussingue Portal.
There are 270 cross passages (CPs), formed in ~135 pairs of cross passages. These have an internal diameter of 3.3 metres (or 4.8 m), and are 9.93 metres in length, gradient of 3.5%. Each cross passage is referenced as "CP" followed by a four-digit number, which is the chainage to the nearest 10 metres. Odd-numbered cross-passages connect to Running Tunnel South, Even distances connect to Running Tunnel North. On the blast doors themselves the number is followed by the letter 'N' or 'S' respectively.
Of the cross-passages, 39 pairs are also fitted with one-way Air Distribution Units (ADU) to allow fresh air to bleed from the service tunnel to the running tunnels. These are fitted above the door bulkhead at every cross passage in the central section, and then at 1.2‒1.4 kilometre distances towards the ends of the tunnels.
Additionally some cross-passages are fitted with smoke detectors (SD) at 1.5 kilometre intervals, these are numbered SDnn where even numbers apply to RTN and odd numbers to RTS.
List of Cross Passages
As of 6 February 2014: 115/270 individual cross-passages cited. 98/135 pair locations cited.
|RTS / TFS||RTN / TFN|
|PK 1003 Interval 1||PK 1003 Interval 2|
|approx 10+400, stairs|
|approx 10+775, stairs||CP 1078 (RTN)|
|barriers; transition||CP 1114 (RTN, entrance)|
|CP 1138 (RTN)|
|CP 1175 (RTS, SD01)||CP 1176 (RTN, SD02)|
|CP 1250 (RTN)|
|CP 1325 (RTS, SD03)||CP 1326 (RTN, SD04)|
|CP 1334? (RTN, suspect)|
|CP 1401 (RTS)||approx 14+005|
|CP 1475 (RTS, SD05)||CP 1476 (RTS, SD06)|
|CP 1625 (RTS, SD07)||CP 1626 (RTN, SD08)|
|CP 1813 (RTS, ADU)||CP 1812 (RTN, ADU)|
|CP 1849 (RTS, SD09)||CP 1850 (RTN, SD10)|
|approx 18+870 (before SVS)|
|approx 19+245 (after SVS)|
|CP 1962 (RTN)|
|@19925, "M1"||CP 1990 (RTN, SD12)|
|CP 2064 (RTS)||@20651, "M3"||CP 2064 (RTN, ADU, large)|
|@21401, "M6"||CP 2140 (RTN)|
|CP 2215 (RTS, SD13)||@22151, "M9"||CP 2214 (RTN, SD14)|
|@23276, "M12A"||CP 2326 (RTN)|
|CP 2365 (RTS, SD15)||@23651, "M13"||CP 2364 (RTN, SD16)|
|CP 2515 (RTS, SD17)||@25151, "M19"||CP 2514 (RTN, SD18)|
|CP 2625 (RTS, SD19)||@26245, "M22B"||CP 2626 (RTN, SD20)|
|CP 2663 (RTS, SD21)||@26607, "M23"||CP 2662 (RTN, SD22)|
|PK 2713 Interval 1/3||PK 2713 Interval 2/4|
|CP 2751 (RTS, SD23, ADU, stairs)||CP 2752 (or CP 2750) (RTN, SD24)|
|CP 2789 (RTS, stairs)|
|CP 2825 (RTS, SD25)||CP 2826 (RTN, SD26)|
|CP 2863 (RTS, SAFE 3U)||CP 2862 (RTN, SAFE 4U)|
|CP 2901 (RTS, SAFE 3U)||CP 2900 (RTN, SAFE 4U)|
|CP 2937 (RTS, SAFE 3U)||CP 2938 (RTN, SAFE 4U)|
|CP 2975 (RTS)||CP 2974 (RTN)|
|CP 3013 (RTS, SD27)||CP 3012 (RTN, SD28)|
|CP 3049 (RTS)||CP 3050 (RTN)|
|CP 3087 (RTS)||CP 3088 (RTN)|
|CP 3213 (RTS, SD29)||CP 3214 (RTN, SD30)|
|CP 3349 (RTS)||@33515, "M44A", "33CP2"||CP 3350 (RTN, @33515)|
|CP 3387 (RTS)||@33890, "M45", "33CP3"||CP 3388 (RTN)|
|@34265, "M46A", "34CP1"|
|@34640, "M47", "34CP2"|
|@35015, "M48A", "35CP1"|
|@35390, "M50", "35CP2"||CP 3538 (RTN)|
|@35765, "M51A", "35CP3"|
|@36140, "M53", "36CP1", ADU|
|@36515, "36CP2", ADU|
|@36890, ADU||CP 3687 (RTS, ADU)|
|@38765, ADU||CP 3864 (RTN, ADU)|
|CP 3913 (RTS, SD35)||@39140, ADU||CP 3912 (RTN, SD36)|
|@40265, ADU||CP 4026 (RTN)|
|CP 4101 (RTS)|
|CP 4131 (RTS)||CP 4132 (RTN, SD40)|
|CP 4163 (RTS)|
|MFT 4173 (STS, SAFE FR)|
|MFT 4175 (?, STS, SAFE FR)|
|CP 4201 (RTS, SD??, SAFE 3F)||CP 4202 (RTN, SD42, SAFE 4F)|
|CP 4239 (RTS, SAFE 3F)||CP 4240 (RTN, SAFE 4F)|
|CP 4277 (RTS, SAFE 3F)||CP 4276 (RTN, SAFE 4F)|
|CP 4282 (RTN, SD??)|
|CP 4351 (RTS, SD??)||CP 4352 (RTN, SD??)|
|CP 4417 (RTS, SD??)||CP 4416 (RTN, SD??)|
|CP 4463 (RTS)||sliding doors||CP 4464 (RTN)|
|PK 4473 Interval 3/5||PK 4473 Interval 4/6|
|CP 4523 (RTS, SD??)||CP 4524 (RTN, SD??)|
|CP 4602 (RTN)|
|CP 4631 (RTS)||CP 4632 (RTN)|
|CP 4671 (RTS)||CP 4672 (RTN)|
|CP 4704 (RTN)|
|CP 4747 (RTS, SD??)||CP 4746 (RTN, SD??)|
|CP 4784 (RTN)|
|CP 4822 (RTN)|
| CP 4863 (RTS)
||large bore||CP 4864 (RTN, SD??)|
|CP 4897 (RTS)||CP 4898 (RTN)|
|CP 4932 (RTN, ?)|
|CP 5015 (RTS, SD??)||CP 5014 (RTN, SD??)|
|CP 5127 (RTS, ADU)|
|approx 53+893||CP 5390 (RTN)|
|CP 5539 (RTS, ADU)||CP 5540 (RTN, ADU)|
|CP 5614 (RTN)|
|CP 5651 (RTS)|
|CP 5689 (RTS, SD61)||CP 5690 (RTN)|
|@57643||CP 5764 (RTN, ADU)|
|CP 5838 (RTN)|
|CP 5877 (RTS)||CP 5876 (RTN)|
|CP 5913 (RTS, SD??)|
|CP 5951 (RTS, portal)|
|PK 6050 Interval 5||PK 6050 Interval 6|
- Incident Control Centre
The Incident Control Centre mimic board contains a full list of Smoke Detector (SD) locations along the middle of the board, most of which align with cross-passages, and the RTN positions of smoke detector stations reversed-engineered from the PDF drawing offsets in the graph on page 29 of http://www.raib.gov.uk/cms_resources.cfm?file=/071023_R372007_Channel_Tunnel.pdf … they match up surprisingly well with the mimic board!
11759.4594835 1176 sd02 13261.4371652 1326 sd04 16261.8161023 1626 sd08 18500.4780963 1850 sd10 19898.7476279 1990 sd12 22140.9857600 2214 sd14 23639.3871595 2364 sd16 25141.3646971 2514 sd18 26260.6959342 2626 sd20 26621.8854059 2662 sd22 27519.4960784 2752 sd24 28259.7566729 2826 sd26 30119.3475442 3012 sd28 32139.8651117 3214 sd30 29811.8001445 2981 fire 19101.2693034 1910 svs-shaft* 27068.9026731 2707 ukxo* 30501.9943249 3050 exitcp*
The laws of physics allow us to make some reasonably good hypotheses. At least a dozen of the cross-passages are funny ones ("specials") and generally avoided for stopping by being marked as "Go-Zones"; most of these also have sliding doors because of space restrictions. The service tunnel tunnels radius minimums are known, as are the absolute maximum CP spacing of 500 metres allowed by the Concession Agreement and the easing under Castle Hill and Holywell Combe where alternative construction techniques were used.
The cross-passages near the two portals and around the crossovers cannot be the standard recipe using level access to platform, as there must be height differential. When then service tunnel is "off-line" it must also dip low enough for the perpendicular walkways to cross under the running tunnels to reach each cross-passage door. Where the main tubes remain adjacent and the service tunnel below these can be arranged in pairs of cross-passage doors "back-to-back", with one set of perpendicular stairs parallel to the main tunnels. Because of the 10.5-metre separation at crossover the caverns, these are not going to fit.
Besides passenger access, there are be engineering needs. The caverns have a cross passage at each end, going to stars behind the ends of the doors.
At the Castle Hill portal, there maybe a CPD for checking the points at CH10+172, this would be pretty soon after the airlock and there is a recess here, but on the south side of the service tunnel. The first proper cross-passage has to be just beyond the maximum reach from the portal of 375 metres (c.CH10+400) to allow maximum dip as the service tunnel climbs down steeply at -3.5%. The cross-passage duck-under has to have NATM clearance of RTS above. The second proper passage will be aligned for points maintenance but less constricted height-wise because of the use of a cut-and-cover slab: however it is (a) limited by start of the Holywell Crossover, and (b) a need for the service tunnel to start climbing at 3.5% back up again, (c) engineering will want access to the points at CH10+775, however this matches with 2*375 metres from the portal.
The will be a side engineering adit for maintaining the blast door in the Holywell crossover at c.10+900. Probably one again for the points CH11+038 (RTN only required). There needs to be a proper cross-passage not later than CH11+150 (3*375m), and this matches with the confirmed CP1114 identified in the RIAB 2006 fire report. It is also where the RTS TBM reception chamber is and these are visible in photographs as a double TBM-reception chamber for ST and RTS (which arrived at different times). Next will be an odd length for the last rings of the TBM drive; there may also be some variation in the section Shakespeare Cliff as RTN will be 20 odd metres longer than RTS by the time it gets to SUD on the outside of the curve.
At Shakespeare cliff the old 1975 service tunnel will come into play and I doubt they will have wanted to break out of it sideways more than necessary, so I'd expect a cross-passage neatly at both ends. Though this is not confirmed.
The pumping stations may have "extra" cross passages within their length. The crossover caverns will have some variation; probably the maximum either side and a short 160-metre pair from the steps in the cavern. The meeting area in the middle appears to be non-standard as this requires various combinations of British tunnels with 1.5-metre rings aligning with French tunnels with 1.6-metre or 1.4-metre rings. Sangatte Shaft may or may not interfere with the regularity as it appears there is likely stairs access here, and finally the French portal has a false façade with escape doors and steps (from the outside) that may or may not be counted as a cross-passage. There is a smoke detector station SD65/SD66 which may also be in the façade and so not a "standard" cross-passage.
These final doors at the French end state:
CC 6049 S
ER 6049 S
ES 6049 S
SP 6049 S
SR 6049 S
CC 6050 N
ER 6050 N
ES 6050 N
SR 6050 N
The adjacent TVM override switch is "
Upon construction, there were 210 technical rooms. These have an internal diameter of 3.3 metres. These are constructed in the same way as cross-passages, but are stub-ended rooms and so only connected at the service tunnel end. Since then, some new rooms were constructed for the SAFE fire extinguishing system.
There are fourteen 21kV sub-stations, numbered ES1‒ES14, spaced at distances of between 2.8‒5.1 kilometres.
TVM430 transmitters and receivers are grouped every 14 kilometres, and feed up to 7 kilometres in each direction to the individual 450-metre long block sections.
Signalling Room 28 was commissioned in 2003 for the purpose of interfacing the concession TVM430 signalling with that of CTRL1.
- Concession Radio (Motorola Starnet MPT1327 standard) base station rooms are located every 1.5 kilometres, with leaky feeder cables spanning out in both directions along the two running tunnels and the service tunnel, each feeder overlapping with the feeder from the next base station for continuious coverage.
- Cab Secure Radio (BR 1845 standard) located in the two running tunnels only, with the same feeder cable on the inner side of the Running Tunnels.
- "Shuttle Radio" (Wideband Broadcast FM 99.8/95.6 MHz whilst in-tunnel; originally 88.8 MHz in-shuttle PA Broadcast?). Frequency split to be English/French or Pop/Kids at various times over the years.
- "Channel Travel Radio" (Wideband Broadcast FM, 107.6/107.7 MHz), funded and broadcast by Eurotunnel as a neutral unbiased information provider until 27 September 2000 and targeted at the motorway approaches to Calais and Folkestone.
- Tactical Radio (UHF, ~16 channels ~415MHz). Uses mobile "STTS-Com" base-stations mounted in a STTS transport vehicles for relay uplink to the incident control centre via the tunnel's fixed optical communications network.
The Alcatel-Lucent's digital installation has 144 sections of leaky feeder, driven by 144 remote units (RU), grouped into 12 cells, and supplied from 4 optical master units (OMU) connected to 4 groups of operator-supplied base transceiver stations (BTS). Each operator has two BTS, one at Sangatte and one at the Lower Shakespeare Cliff/Samphire Hoe. Each BTS drives three cells: French operators feed Running Tunnel South and British operators feed Running Tunnel North. The cells, from east-to-west are of lengths 8.9 km, 10.1 km, 8.6 km, 7.6 km, 7.2 km, 8.1 km. The leaky-feeder is broken into 750-metre intervals, and placed at a height of 2 metres on the outer side of the Running Tunnels: The base-stations can generate:
- GSM-R (sub-GSM900)
- GSM-P (GSM900 + DCS1800)
- 3G (WCDMA/UMTS2100)
- 4G (LTE 2600 MHz)
- TETRA STP8000 (handheld radios purchased in 2009 for Project Salamander)
Within the two running tunnels there are four Stations d'Attaque du FEu (SAFE) which are water-mist fight-fighting stations retro-fitted in the central intervals of the tunnel. There two pairs of parallel stations. One is located on the inner side of each crossover cavern. Each SAFE facility is 870 metres long, made up of twenty-nine 30-metre-long individually-controlled sections, each of 15 mist nozzles per side (30 per section, 870 nozzles per station). (Eurotunnel drove alot of journalists into the tunnel on 1 February 2012, and then proceeded to drench them on the first attempt! These are for Project Salamander, and also to allow the tunnel to accept eventually to accept TSI-compliant rolling stock with 15-minute fire-ratings.
Additional equipment rooms had to be created near the SAFE zones to house the high-pressure pumps for each installation. These were formed by breaking out from each side of the service tunnel. Additionally a large number of new pipe bores were run from the service tunnel to the running tunnel at 60-metre intervals, presumably to avoid the SAFE station infrastructure from being exposed to fire in the way at the running tunnel fire hydrants were in the earlier fires.
Piston Relief Ducts
There are 194 (or 196) piston/pressure relief ducts (PRDs) at 250-metre spacing. These have an internal diameter of 2 metres, are 23.33 metres long, with an 18-metre radius. The butterfly shut-off valves alternate between being at the north, or south end of each PRD.
|PRD 5343 N|
There are four sets of crossovers. Two are undersea scissors crossovers, plus crossover is located on outside of the Beussingue Portal on land, and one is on/under land, located partially inside, and partially outside of the Castle Hill portal.
The Castle Hill/Holywell Crossover is the start of intervals 1 and 2. A facing crossover starts outside the Castle Hill portal with a set of points that separates from the Down Fast, crosses through the portal at CH10+025 and connects to Running Tunnel South at CH10+170 (or CH10+172). Length ~210 metres.
The trailing component of the crossover leaves Running Tunnel South at CH10+775 crosses through a blast door and reaches Running Tunnel North at CH11+038. Length ~263 metres.
The UK Crossover Cavern is 15.4 metres high, 163.8 metres long and 21.2 metres wide. This is located at chainage CH27+000—CH27+150. It lies at an angle of ~300 degrees to north. It is at CH27.1.
The Beussingue crossover facility is in the Beussingue trench, outside of the Beussingue portal. It consists of six sets of points. It provides a facing point from each running lines to a third centrally-placed single track, and then back again to each running line. This begins at CH 60+609 and heads eastwards.
One minor pumping station was constructed with the 1975 Adit A1 works. The 1987 Channel Tunnel constructed a further four major pumping stations, of which only three are fitted out with equipment and usable. There are G, K, W3, and an unused one at Sangatte U. Each of the major pumping stations (station de pompage) consists of a long sump perpendicular to principle tunnels, and two longitudinal equipment galleries (galeries d'équipements) between the service tunnel and each running station.
Pumping Station D
Pumping Station D dates from the 1974 Channel Tunnel. It is at the bottom of Adit A1, off to the south of the Adit. This is part of the Shakespeare Underground Development (SUD). It is served by Electrical sub-station ES-3.
Pumping Station G
Pumping Station G, or Pumping Station W1 is at chainage CH25.0 Separation of 38 metres between running-tunnel centrelines. The low-point is at CH24.9. It is served by Electrical sub-station ES-5.
Pumping Station K
Pumping Station K, or Pumping Station W2 is at chainage CH35.2 Separation of 43 metres at CH34.8. It is served by Electrical sub-station ES-7, which is also the mid-tunnel isolator.
Pumping Station W3
Pumping Station U
This is at Sangatte. CH57+247. It (would be) served by Electrical sub-station ES-13.
Electrical mid-point CH 35.3.
Fire hydrant mid-point valve CH 36.21.
The meeting place of the tunnel drives. This is a different location for each tunnel drive, but is roughly in the middle of the English Channel at KM41. This is PK15.775 from the French coast. The British Tunnel Boring Machines were angled and driven downwards to be permanently buried.
This is in the service tunnel and where everyone stops to write their signature and "I woz here" etc, on the wall. It is labelled with a vertical sign saying "MID-POINT".
Channel Tunnel Chainage
The Channel Tunnel Chainage is a metric east-to-west linear measurement along the tunnels in metres/kilometres from an arbitrary point in the region of Westenhanger in Kent, heading towards to France. The UK Castle Hill Portal is at a nominal chainage of CH10 (~ +10,025 metres) and the Sangatte Poral at a nominal chainage of CH60.5 (~ +60,518 metres). This may be referenced as kilometre (KM) or kilometre point (KP).
Ring counts are also used for chainage. Each complete ring is 1.5 metres wide.
Channel Tunnel Grid
- This needs clarifying, there are conflicting definitions getting mixed up
The Channel Tunnel Grid or CTG86 or RTM87 ("Reseau Trans Mercator" 1987) are variants of the grid system used for constructions. If we get a data dump off Eurotunnel it will likely be in one of these grid systems. CTG86 and RTM87 are a "Cylindrical Orthomorphic Transverse Mercator" projection centred on 1°30'E by 49°N. CTG is a UTM 31U metric projection used in the earlier works, but with a false origin offset of X0=40,000m and Y0=1,000m (to avoid negative grid references).
An example grid location (approximate east end of UK crossover cavern) will look something like "31U 386700m 5660000m", "31U 386700 5660000" or "386700 5660000". This translates to approximately 51.0803N 1.3825E. Of the literature published at the time, "Engineering geology of the Channel Tunnel" contains several examples as does "The Channel Tunnel: Tunnels".
Channel Tunnel Height Datum
The Channel Tunnel Height Datum (CTHD) or Channel Tunnel Ordnance Datum is a metric vertical datum. The Channel Tunnel OD has its zero point 200 metres below the standard British Ordnance Newlyn (ODN, approximately 200 metres below sea-level). It produced the NTM88 levelling ("Niveau TransManche" 1988). If we get any vertical data from Eurotunnel it will likely be in this format. Vertical data is very widely published, and has also been independently created by the Edinburgh University gravimetric survey.
18 November 1996, Running Tunnel South, Interval 3, HGV Shuttle 7539
- CP 4131 (evacuation, FR tackle fire)
- CP 4201 (UK tackle fire)
- CH 4186‒4191 Extreme damage (50 m)
- CH 4180‒4201 Very severe damage (210 m)
- CH 4180‒4209 Severe damage (290 m)
- CH 4172—4220 Substantial damage (480 m)
21 August 2006, Running Tunnel North, Interval 4, HGV Shuttle 7370
11 September 2008, Running Tunnel North, Interval 6, HGV Shuttle 7412
- CH 48+417‒48+433 Greatest damage (16 m)
- CH 48+417‒48.701 Damage (284 m)
- CP 4822 (fire fighting)
- CP 4864 (fire fighting)
- CP 4898 (evacuation)
- CP 4932 (opened initially, used by two people?)
- Hesters, Patrick (6 May 1994). "Les projets fous" (video). http://www.ina.fr/video/CAC94048184/les-projets-fous-video.html.
- "Site Name: Channel Tunnel - 1880 attempt". Subterranea Britannica. 1984–1988. http://www.subbrit.org.uk/sb-sites/sites/c/channel_tunnel_1880_attempt/index1.shtml.
- "The Channel Tunnel: French section". 1994. p. 6. http://books.google.co.uk/books?id=VtfyR-GbaacC&pg=PA6. "two shafts and an adit 210 m in diameter and 1669 m long were excavated at Sangatte under the supervision of the engineer, C. Breton Template:Sic" . Nota bene: actually Ludovic-Joseph Breton
- Sartiaux, Albert (1906). "The Channel Tunnel". p. 37. http://www.forgottenbooks.org/download_pdf/The_Channel_Tunnel_1000546865.pdf. "submarine boring was tried and continued until March, 1883, by the French Company under the direction of the eminent director of works Mr. L. Breton, … sinking on shore at Sangatte a shaft to the depth of about 65 yards below sea-level and of greater diameter, and in starting from the bottom of this shaft a gallery to be used for experimental purposes 2¼ yards in diameter, penetrating the before-mentioned layer of Cenomanian Chalk for a distance of 1 mile 250 yards under the sea."
- Decq, Gérard (5 January 1974). "Travaux du tunnel sous La Manche" (film). http://www.ina.fr/video/RCC9709302108.
- Coudert, Philippe (20 January 1975). "Historique et réactions sur le tunnel sous La Manche" (film). http://www.ina.fr/video/RCC9711103028/historique-et-reactions-sur-le-tunnel-sous-la-manche-video.html.
- Dupagny, Gérard (28 September 1981). "Le tunnel sous La Manche à Boulogne sur Mer" (film). http://www.ina.fr/video/RCC00000567/le-tunnel-sous-la-manche-a-boulogne-sur-mer-video.html.
- Keefe, John; Portillo, Michael (27 January 2011). "Great British Railway Journeys: Sandwich to Folkestone" (series 2 episode 19). http://www.bbc.co.uk/programmes/b00y47ts.
- Hipkin, Roger G.; Kirby, Jonathan F.; Charles, Kate (1995). "British and French Gravity Datums Connected via the Channel Tunnel". http://link.springer.com/chapter/10.1007%2F978-3-642-79721-7_8.
- "Technical Investigation Report concerning the Fire on Eurotunnel Freight Shuttle 7412 on 11 September 2008". RIAB. http://www.raib.gov.uk/cms_resources.cfm?file=/101122_ReportET2010_eurotunnel_eng.pdf.
- cite book|title=Engineering geology of the Channel Tunnel|first=Colin S.|last=Harris|pages=339
- "Tunnel Sous la Manche, Profil Geologique Simplifie le Long du Tunnel Ferroviaire (Vue en Plan, Coupes Transversales)" (in fr). http://www.sussex.ac.uk/geography/researchprojects/coastview/Offshore/Channel_tunneL_geology.jpg.
- "The Channel Tunnel: Tunnels"
- "Des ouvrages hors du commun". 2 April 2013. http://www.batisseurs-tunnel.com/amicale/Memoire%20du%20chantier%20tunnel/1.1.1.pdf. Retrieved 6 February 2014.
- The Channel Tunnel: French section, page 64.
- Pompée, Pierre-Jean. "Channel Tunnel Tunnels Construction". http://www.batisseurs-tunnel.com/amicale/doc%20UK/3%20Tunnels%20Tunnel%20sous%20La%20Manche_C%20.pdf.
- "The Tunnel: Across The Divide" (offset 00:51). http://www.sky.com/tv/show/the-tunnel/video/across-the-divide. Retrieved 2 February 2014. "AL 6043"
- The Channel Tunnel: Transport systems, Page 41
- John, M.; Crighton, G.S. (1990) "Monitoring and interpreting of results of geotechnical measurements for NATM linings for the Channel Tunnel" in "Geotechnical instrumentation in practice". ISBN10 07277-1515-1
- Korittke, N. (1989). "Influence of horizontal Refraction on the traverse Measurements in Tunnels with Small Diameters". Bochum, W-Germany: Institute for Deposits and Surveying, DMT. pp. 13–17. http://www.slac.stanford.edu/econf/C9009106/papers/023.PDF.
- Tunnels and Metropolises: Proceedings of the World Tunnel Congress, Volume 2, page 826.
- "Navigation von Rohrvortrieben". UmweltBau. 2004. pp. 6–8. http://www.nodig-bau.de/praxisberichte/bi_05-04_06-08.pdf. "Widmung: Während unseres Messeinsatzes in St. Petersburg ist unser Kollege Norbert Korittke, der dieses Projekt von Seiten DMT verantwortlich organisierte, nach langer schwerer Krankheit verstorben. Wir haben diesen Messeinsatz Norbert Korittke gewidmet."
- Norittke, Norbert (1997). "Zur Anwendung hochpräziser Kreiselmessungen im Bergbau und Tunnelbau" (in de). p. 131.
- Penny, Charles. "Channel Tunnel transport system". p.96. "Longitudinal Profile of the Tunnel".
- Penny, Charles. "Channel Tunnel transport system". p.175
- Pompée, Pierre-Jean (19 June 2009). "Channel Tunnel Project Overview". http://www.batisseurs-tunnel.com/amicale/doc%20UK/1%20Le%20Projet%20Tunnel%20sous%20La%20Manche_C.pdf.
- "Inquiry into the fire on Heavy Goods Vehicle shuttle 7539 on 18 November 1996". Channel Tunnel Safety Authority. http://www.railwaysarchive.co.uk/documents/CTSA_ChanTun1996.pdf.
- "All Over the Place 6/13" (offset 09:05). CBBC. 29 February 2012. "CP 1078 on water pipe"
- "Fire on HGV shuttle in the Channel Tunnel 21 August 2006". RIAB. http://www.raib.gov.uk/cms_resources.cfm?file=/071023_R372007_Channel_Tunnel.pdf.
- "Michael Smith's Drivetime 6/6" (offset 14:27). 26 March 2009. "CP 1114 with barriers at both sides; at transition of rectangular to circular service tunnel"
- "Crimewatch Roadshow" (offset 35:38). BBC One HD. 28 June 2013. "CP 1138 on water pipe"
- Incident Control Centre Mimick Board
- "Fire on HGV shuttle in the Channel Tunnel 21 August 2006". RIAB. p. 29. http://www.raib.gov.uk/cms_resources.cfm?file=/071023_R372007_Channel_Tunnel.pdf.
- "Super Structures: Eurotunnel Part 4"
- "The Tunnel (Inside The Tunnel)" (video, offset 00:36). Sky Website. Sky Atlantic/CANAL+. http://youtu.be/MjttDCoKQRM?t=5m20s. Retrieved 2014-02-02. "Registration KU56 WSW, underneath fire-main pipe "CP1401" (on left), looking west"
- "Fire on HGV shuttle in the Channel Tunnel 21 August 2006". RIAB. http://www.raib.gov.uk/cms_resources.cfm?file=/071023_R372007_Channel_Tunnel.pdf.
- "Investigation into Stoppage of Five Eurostar Trains Occuring in the Channel Tunnel on 18 and 19 December 2009". Eurotunnel. 22 March 2010. http://assets.dft.gov.uk/publications/pgr-rail-pi-eurostarprogressreport-pdf/eurtunnelrecommendations.pdf.
- "All Over the Place 6/13" (offset 09:06). CBBC. 29 February 2012. "CP 2065 S"
- "All Over the Place 6/13" (offset 09:27). CBBC. 29 February 2012. "CP 2064 N"
- "Report by the Channel Tunnel Intergovernmental Commission on Safety in the Channel Tunnel Fixed Link During 2009" (Also has terminal signalling maps on p.30).
- Bouthors, Bruno (19 October 2012). "Présentation de Bruno Bouthors pour conférence à Madrid". p. 24. http://www.ita-aites.org/fileadmin/filemounts/COSUF_Ressources/Pdf/3-__-_Bruno_Bouthors_-_Pr__sentation_de_Bruno_Bouthors_pour_conf__rence__%C3%A1_Madrid.pdf.
- Penny, Charles. "Template:Citation error". p. 183.
- "The Channel Tunnel In Focus". http://www.means-of-escape.com/industry-news/news76.aspx.
- "English Channel Tunnel November 18, 1996". http://www.nfpa.org/assets/files/PDF/ChunnelSummary.pdf.
- Maquaire, C. (8 March 2012). "SAFE Station". p. 10. http://www.i-trans.org/mediatheque/pdf/RIM_conf_2012/eurotunel.pdf.
- "CP 4202 N: Coquelles (62): présentation du système SAFE d'Eurotunnel (01/02/2011)" (photograph). Andia. 1 February 2011. http://www.andia.fr/consulter/Detail.asp?MotRecherche=+214971. Retrieved 13 July 2013.
- "Les Equipments des Tunnels". 19 July 2009. http://www.batisseurs-tunnel.com/amicale/expo/11.pdf. Retrieved 14 July 2013.
- Maquaire, Christian; Zanker, Philippe; Petit, Bertrand; Mauvisseau, Véronique; Setec, Michel (July/August 2009). "Réparation en moins de quatre mois du tunnel sous la Manche après l’incendie de septembre 2008". p. 183. http://www.aftes.asso.fr/doc_gd_public/article_fichier/T214-179a186-Sous%20la%20Manche.pdf.
- "Feu Tunnel Hydratation" (photograph). Service départemental d'incendie et de secours 62. http://www.sdis62.fr/var/storage/images/media/images/feu_tunnel_hydratation/2604-1-fre-FR/feu_tunnel_hydratation.jpg. Retrieved 15 July 2013.
- Fires in Channel Tunnel on Eurotunnel freight shuttles (IGC)
- "BBC News at Ten" (offset 00:18). BBC News 24. 10 December 2008. "CP 4898 seen from RTN during repairs. CP 5890 from heading westbound in RTN."
- "Tunnel-4-m" (photograph). http://www.eurotunnelgroup.com/uploadedImages/assets-uk/Media/MediaItem/Fixed-Link-Eurotunnel/Tunnel-4-m.jpg. "CP 5127 S"
- "Legend: 127F1030008" (photograph). http://www.eurotunnelgroup.com/assets/0/519/661/662/663/df97817d-a4cb-45c5-9058-8b6c598e92ee.jpg. "CP 5690 N"
- "C'est pas sorcier: L'Eurotunnel". http://www.youtube.com/watch?v=U-jWSlqjOho.
- "The Tunnel (Full Episode 1)" (video, offset 05:20). YouTube. Sky Atlantic/CANAL+. http://youtu.be/MjttDCoKQRM?t=5m20s. Retrieved 2014-02-02.
- "CP 5876 N" (photo). Eurotunnel Group. http://www.eurotunnelgroup.com/uploadedImages/assets-uk/Tunnel-Infrastructure/Infrastructure/The-Channel-Tunnel/The%20Channel%20Tunnel%20pic4.jpg.
- Terdiman, Daniel (1 July 2011). "Behind the scenes: inside the Chunnel: CP 5876 N". CNET Australia. http://cdn.cnet.com.au/story_media/339317816/chunnel_18.jpg. Retrieved 15 July 2013.
- "The Channel Fixed Link Concession Agreement". 14 March 1986. http://www.channeltunneligc.co.uk/spip.php?action=acceder_document&arg=94&cle=eb523418f351e57679238f0cf5452e8d&file=pdf%2FConcession_Agreement.pdf.
- Kirkland, C.J.; "Engineering the Channel Tunnel".
- Quatre, Michel (26 October 2004). "Annual Report 2003 - 2004". Health and Safety Executive. http://web.archive.org/web/20050520110259/http://www.hse.gov.uk/railways/ctsa0304.pdf. Retrieved 14 July 2013.
- "Channel Tunnel radio station closes". Media Week. 29 September 2000. http://www.prweek.com/uk/news/506676/Channel-Tunnel-radio-station-closes/.
- "107.6 FM: This is Channel Travel Radio"". Eurotunnel News. June 1995. p. 15.
- Rémond, Christian (21 February 2013). "GSM-P Global Architecture". http://www.terrapinn.com/2013/metro-rail/data/christian-remond.ppt.
- Plus partially from memory, personal conversation with an Alcatel employee.
- "Eurotunnel chooses Sepura STP8000 radio". 23 August 2011. http://www.sepura.com/news-and-events/news/2009/eurotunnel-chooses-sepura-stp8000-radio-.aspx.
- Hope, Richard (7 February 2011). "Eurotunnel demonstrates €20m fire suppression system". Railway Gazette. http://www.railwaygazette.com/news/single-view/view/eurotunnel-demonstrates-EUR20m-fire-suppression-system.html.
- "Channel Tunnel gets £20m fire protection system". BBC News Online. 1 February 2011. http://www.bbc.co.uk/news/uk-england-kent-12340538.
- Reynold, Patrick (February 2011). "Fire fighting system unveiled by Eurotunnel". Tunnel Talk. http://www.tunneltalk.com/Eurotunnel-Feb11-Fire-fighting-system.php.
- "PK 1190" (photograph showing PRD opposite). http://www.halcrow.com/Global/Images/history/Channel_Tunnel_1.jpg.
- Pompée, Pierre-Jean (19 April 2007). "Channel Tunnel Special Underground Works". http://www.batisseurs-tunnel.com/amicale/doc%20UK/5%20Ouvrages%20Speciaux%20Tunnel%20sous%20La%20Manche_C%20.pdf.
- Penny, Charles. "Channel Tunnel transport system". p.95.
- "Channel tunnel: 11th of September 2008 fire: Civil works damage investigation". Tunnels est Espace Souterrain n°217. January/February 2010. http://www.aftes.asso.fr/doc_gd_public/article_fichier/T217-17a26TunnelManche.pdf.
- In the CANAL+/Sky Atlantic drama serial The Tunnel a substitute pair of lit-up yellow triangular boxes showing "MID POINT"/"POINT MEDIAN" and "436:084" (surrounded by yellow arrows with flags) were used. — Plunkett, John (13 October 2013). "Sky's remake of The Bridge is set in the Channel tunnel – in English and French". The Guardian. http://www.theguardian.com/tv-and-radio/2013/oct/13/sky-bridge-channel-tunnel-remake-clemence-poesy. Retrieved 2 February 2014. "The midpoint in the tunnel, marked with a bright yellow point median sign, really exists, Moll said, but the film crew did not venture all the way to the middle."
- Penny, Charles. Channel Tunnel transport system. p.179.